Radiation curable acyclic siliconemodified paint binders



April 8, 1969 w. J. BURLANT ET AL 3,437,513

RADIATION CURABLE ACYCLIC SILICONEMODIFIED PAINT BINDERS 'sheet Filed Aug. 13. 1965 ATTORNEYS April 8, 1969 w. J. BURLANT ET Al. 3,437,513

RADIATION CURABLE ACYCLIC SILICONE-MODIFIED PAINT BINDERS Sheet Filed Aug. 13. 1965 Nwl INVENTORS I ATTORNEYS United States atent O 3,437,513 RADIATION CURABLE ACYCLIC SILICONE- MODIFIED PAINT BINDERS William J. Burlant, Detroit, and Ivan H. rIsou, Pontiac, Mich., assignors to Ford Motor Company, Dearborn, Mich., a corporation of Delaware Filed Aug. 13, 1965, Ser. No. 487,100 Int. Cl. B44d 1/36; C09d 3/48, 11/10 U.S. Cl. 117-9331 22. Claims ABSTRACT F THE DISCLOSURE A radiation polymerizable paint binder solution of a polysiloxane modified organic resin in vinyl monomers. The paint binder resin of this invention has a molecular weight in excess of about 1,000, contains about 0.5 to about 3 alpha-beta olefinic unsaturation units per 1,000 units molecular weight, and is further characterized in that at least wt. percent thereof is derived from an acyclic siloxane.

This invention relates to the art of coating and is primarily concerned with method and means for providing articles of manufacture, particularly wood and/ or metal surfaces thereof with decorative and weather resistant coatings, including improved paints for such purpose, their preparation, application to a substrate and polymerization thereon. More particularly, this invention relates to an improved paint binder comprising an improved silicone-modified, organic resin and a vinyl monomer which are copolymerizable by ionizing radiation.

In this application the term paint is meant to include finely ground pigment and/ or filler in the binder, the binder without pigment and/or filler or having very little of the same, which can he tinted if desired, and other surface coating compositions containing the binder which might be considered to be broadly analogous to enamel, Varnish, or lacquer bases. Thus, the binder which is ultimately converted to a durable film resistant to conventional curing, can be all or virtually all that is used to form the film, or it can be a vehicle for pigmentary and/ or mineral filler material.

The term ionizing radiation as employed herein means radiation having sufficient energy to remove an electron from a gas atom, forming an ion pair, and hence radiation with energy of, or equivalent to about 5,000 electron volts is operative for effecting polymerization of the paint films herein disclosed. The preferred method of curing films of the instant paint binders upon the substrates to which they have been applied is by subjecting such films to a beam of polymerization effecting electrons which at its source of emission is within the range of, or equivalent to, 150,000 to 450,000 electron volts. In this method of curing, it is preferred to employ a minimum of 25,000 electron volts per inch of distance between the radiation emitter and the workpiece where the intervening space is occupied by air. Adjustment is made for the relative resistance of the intervening gas which is preferably an oxygen-free, inert gas such as nitrogen or helium. It is, however, within the scope of this invention to effect polymerization using either that which is conventionally termed high energy particle radiation or ionizing electromagnetic radiation.

The paint binders of this invention comprise an irnproved, silicone-modified, organic resin having a molecular weight in excess of about 1,000 advantageously about 1,000 to about 50,000, and preferably about 2,000 to about 20,000, and about 0.5 to about 3, preferably about l to about 2, and more preferably about 1.25 to about 1.75 olefinic unsaturation units per 1,000 units molecular 3,437,513 Patented Apr. 8, 1969 weight, and at least one, preferably two dissimilar vinyl monomers, e.g. a vinyl hydrocarbon such as styrene and an acrylic monomer such as methyl methacrylate. The term vinyl as employed herein refers to an organic compound having a rice terminal group.

The films formed from the preferred embodiments of the paints of this invention are cured at relatively 10W temperatures, e.g. between room temperature (20 to 25 C.) and the temperature at which significant vaporization of its most volatile component is initiated, ordinarily be-V tween 20 and 70 C. The radiation energy is applied at dose rates of about 0.1 to about mrad per second upon a preferably moving workpiece with the coating receiving a total dose in the range of about 0.1 to about 100, preferably about l to 25, mrad. Such films are converted by the electron beam into tenaciously bound, wear and weather resistant, coatings which meet the following specifications:

Substrate Requirements of Test Wood or metal... Room temperature water soak.

Withstand 240 hours immersion in water at 20 to 25 C. (68 to 77 F.) without significant loss of gloss or tllm integrity, l.e. without blistering, cheeking, cracking or peeling.

Withstand 25 cycles, each 4 hours immersion in boiling Water followed by 15 hours drying at 62 to 63 C. (about 144 to about 146 FJ, without significant loss of gloss or film integrity.

Metal Elongation Withstand 25% elongation without rupture-1 to 2 mil coating, $6 mandrel.

Wood or metal... Ultraviolet Withstand 2,000 hours exposure in Standard Atlas Ultraviolet Carbon ArcWeatherometer test Without significant chalking and without loss of gloss or film integrity.

Wood Cyclic boiling and baking.

The preferred silicone-modified resins employed herein are polyester type resins with the aforementioned degree of unsaturation, a molecular weight in excess of about 1,000, and having incorporated therein an acyclic siloxane having prior to its incorporation a reactive hydroxyl or hydrocarbonoxy group bonded to at least two of its silicon atoms. The term siloxane as employed herein refers to a compound containing a -sii-o-slior JJ-o-slil l I I linkage, with the remaining valences being satisfied by a hydrocarbon radical, a hydrocarbonoxy group, hydrogen, a hydroxyl group, or an oxygen atom which interconnects the silicon atom providing such Valence with another silicon atom. The acyclic siloxane molecules for use in this invention advantageously contain at least three silicon atoms per molecule with corresponding oxygen linkages. The preferred siloxanes are represented by the following general formula:

if t X X-Sli-O- Si-O Si-X X X n X wherein n is at least 1 and X is (a) a C1 to C8 monovalent hydrocarbon radical, preferably a C1 to C4 alkyl radical, or (b) C1 to C8 monovalent hydrocarbonoxy radical, preferably a C1 to C4 alkoxy radical, or (c) a hydroxyl radical,

or (d) hydrogenwith at least two of the X groups separated by a linkage being either (b) or (c).

A variety of methods are known to the art for preparmg siloxanes. These include controlled hydrolysis of silanes, polymerization or" a lower molecular weight siloxane in the presence of an alkoxysilane, reacting silicon tetrachloride with an alcohol, etc. The preparation of siloxanes and their incorporation into organic resins is disclosed in U.S. Patents 3,154,597, 3,074,904, 3,044,980, 3,044,979, 3,015,637, 2,996,479, 2,973,287, 2,937,230, and 2,909,549.

The starting resin or monomer with which the siloxane is reacted preferably contains a minimum of hydroxyl groups over the number required to react with the reactive hydroxyl or hydrocarbonoxy groups on the siloxane molecules to be incorporated in the resin. At least two of such reactive groups on the siloxane should be reacted with the starting resin or monomer and in one embodiment remaining hydroxyl or hydrocarbonoxy groups upon the siloxane are subsequently reacted with another monomer as hereinafter more fully explained. The nal resin prior to its radiation copolymerization with vinyl monomers advantageously contains from about to about 50, preferably about to about 40, wt. percent silicones, i.e. structure derived from siloxanes.

In one preferred embodiment a silicone-modified polyester type resin is prepared by lirst reacting the acyclic siloxane wit-h a polyhydric alcohol, preferably a branched chain polyhydric alcohol such as neopentyl glycol, and subsequently reacting the first product with an acyclic, alpha-beta unsaturated, dicarboxylic acid or the anhydride thereof, eg. maleic anhydride, and a cyclic, aliphatic, dicarboxylic acid or its anhydride, eg. tetrahydrophthalic anhydride or 1,2-cyclohexane dicarboxylic acid.

In another embodiment the polyester is formed first by reacting the aforementioned polyhydric alcohol, the acyclic, alpha-beta unsaturated, dicarboxylic acid or anhydride and the cyclic, aliphatic, dicarboxylic acid or anhydride either with or without a straight chain polyhydric alcohol, e.g. a propane or butane diol, and subsequently reacting this product with t-he siloxane.

In another embodiment an unsaturated polyester is formed as in the previously described embodiments or a saturated type polyester is formed by substituting a saturated acyclic dibasic acid such as succinic acid for the maleic anhydride and after reaction of the siloxane with monomer or polymer as the case may be, the remaining hydroxyl or hydrocarbonoxy groups on the siloxane are reacted with suitably unsaturated hydroxylated monomers or low molecular weight esters, eg. the reaction product of maleic anhydride and a polyhydric alcohol, provide the desired unsaturation for polymerization.

In another embodiment a hydroxylated vinyl resin is prepared by reacting vinyl monomers, e.g. acrylic acid, methacrylic acid and esters thereof, at least one of which is a hydroxylated monomer such as Z-hydroxyethyl methacrylate. A portion of the hydroxyl or hydrocarbonoxy groups of the siloxane are reacted with the hydroxyl groups of the resin and the remainder are subsequently reacted with a hydroxylated unsaturated compound.

In the accompanying drawing, there is schematically illustrated two methods for carrying out the process of this invention.

The silicone-modified resins in the exemplary paint binders each have molecular weights in excess of 1,000, a degree of unsaturation as hereinbefore dened and when applied and cured in accordance with this invention meet the specifications hereinbefore set forth:

4 EXAMPLE 1 A silicone-modified polyester, paint binder resin is prepared in the following manner:

To a reaction vessel are charged 1330 lbs. of neopentyl glycol and 1080 lbs. of a commercially available methoxylated partial hydrolysate of monophenyl and phenylmethyl silanes consisting essentially of dimethyltriphenyltrimethoxytrisiloxane (Dow Corning-Sylkyd 50) and have the following typical properties:

Average molecular weight 470 Combining weight 155 Specific gravity at 77 F 1.105 Viscosity at 77 F., centistokes 13 The charge is heated to about 345 F. (174 C.) until about 215 lbs. methanol are removed overhead. The charge is cooled to about 250 F. (121 C.) after which there is added 196 lbs. maleic anhydride, 964 lbs. tetrahydrophthalic anhydride, 2.2 lbs. dibutyl tin oxide and 150 lbs. xylene. The temperature of the charge is raised slowly to about 420 F. (215 C.) and this temperature is maintained until the resulting resin has an acid number of 10. A vacuum is pulled to remove the xylene and 6l lbs. hydroquinone are charged and the charge is cooled to 200 F. and dumped into a mixing tank with 780 lbs. styrene.

A white mill base is then prepared by mixing 3050 lbs. of Ti02, 1805 lbs. of resin, prepared as in the preceding paragraph, 146 lbs. of styrene, 507 lbs. of methyl methacrylate, and 2O lbs. of Bakers M.P.A., a wax-like, high molecular weight, castor oil derivative to facilitate the grinding through viscosity adjustment and assist in retention of pigment dispersion in the grind, and passing the foregoing mixture through a conventional sand grinder.

This mill base is further diluted with styrene and methyl methacrylate in amounts such as to provide a paint comprising about 40% resin, 30% styrene and 30% methyl methacrylate. A film of the resulting paint is sprayed upon wood and metal panels and irradiated by an electron beam under the following conditions:

Potential kv 295 Current milliampere 1 Distance, emitter to workpiece inches 10 Line speed cm./sec 1.6

Passes 2 Total dosage mrad-- 10 EXAMPLE 2 A silicone-modified, polyester, -paint concentrate is prepared from the following components:

Parts by weight White mill base from Example 1 5565 Silicone-modified polyester resin prepared as in Example 1 1785 Styrene Methyl methacrylate 1552 Red mill base 198 The red mill base above referred to is prepared by first admixing parts by weight of a 50% xylene solution of a convention acrylic paint binder resin (Gardner- Holdt vis. at 77 `F. WX), 400 parts by weight burnt sienna pigment, and 130 parts by weight xylene. This mixture is ground for 40 hours in a steel ball mill to a ineness of 8 Heg. after which 340 parts by weight of the same acrylic resin are added.

The above referred to paint concentrate is diluted with styrene and methyl methacrylate to provide a paint containing about 40% resin, 30% styrene, 30% methyl methacrylate, sprayed on wocd and metal panels and irradiated as in the previous example.

EXAMPLE 3 The procedure of 'Example 2 is repeated using the following materials to prepare the paint concentrate:

Parts by weight Green mill base 267 The green mill base above referred to is prepared by first admixing 120 parts by weight a 50% xylene solution of a conventional acrylic paint binder resin (Gardner- Holdt vis. at 77 F. WX), 60 parts by Weight phthalocyanine green, 61 parts by weight xylene. This mix is ground 48 hours in a steel ball mill to 8 Heg. after which 240 parts by weight of the acrylic polymer above mentioned and 60 parts by weight xylene are added and the mix is ground for an additional 2 hours. To the latter grind is added 264 parts by weight of the same acrylic polymer, 130 parts by weight of butylated melamine formaldehyde resin (60% solids, 20% xylene, 20% butanol) and 65 parts by weight xylene.

The paint concentrate thus prepared is diluted with styrene and methyl methacrylate to provide paints containing the following:

Resin, Styrene, Methyl methacpercent percent rylate, percent These paints are sprayed on wood and on metal panels and cured by irradiation as in the preceding examples.

EXAMPLE 4 EXAMPLE 5 The procedure of Example l is repeated except for the difference that an equivalent amount dibutoxy tetramethyldisiloxane is substituted for the dimethyltriphenyltrimethoxytrisiloxane.

EXAMPLE 6 The procedure of Example 1 is repeated except for the difference that an equivalent amount of pentamethyltrimethoxytrisiloxane is substituted for the dimethyltriphenyltrimethoxytrisiloxane.

EXAMPLE 7 A resin is prepared from the following monomers:

Mols Grams Maleic anhydride 3. G 353.0 Tetrahydrophthalie anhydr 6. 4 973. S N eopentyl glycol 14. 0 1, 458. 1

A fusion cook of the tetrahydrophthalic anhydride and neopentyl glycol is carried out over a 23-hour period. Water comes over at 165 C. and a maximum temperature of 180 C. is recorded. The resulting resin has an acid number of below and is cooled to room temperature after which the maleic anhydride is added with 1.39 grams hydroquinone and 300 cc. xylene. The charge is heated to an acid number of 10 with water coming over at about 140 C. and a maximum temperature of 180 C. recorded.

A 25% silicone-modied resin is prepared using 503.4 grams of the above resin and 167.8 grams of dimethyltriphenyltrimethoxytrisiloxane. The charge is heated for CTI about 3 hours with methanol coming over at about 120 C. and a maximum temperature of 163 C. is recorded. The charge is then cooled rapidly to about 100 C. at which time 0.106 gram hydroquinone is added and at C., 212.3 grams styrene are added.

A paint lbinder is prepared which includes 50 parts by weight of the above silicone-modified resin, 25 parts by weight styrene and 25 parts by weight of methyl methacrylate. The binder is sprayed upon wood and metal panels and irradiated as in the previous examples. After 8 passes the coating exhibits a Sward Hardness of 18.

Another paint binder is prepared using 25 parts by Weight of the foregoing silicone-modified resin, 10 parts by weight methyl methacrylate, lO parts by weight styrene and 5 parts by weight ethylene glycol dimethacrylate. The binder is sprayed upon wood and metal panels and irradiated as in the preceding examples. After 4 and 6 passes the coating exhibits a Sward Hardness of 1618 and 26-28 respectively.

A mill base is prepared using the following ingredients:

Parts by weight TiO2 600 Silicone-modified resin, this example 300 Styrene Methyl methacrylate 100 This mix was ground 17 hours in a pebble mill. A paint was prepared using the following ingredients:

Parts by weight Above mill base Silicone-modified resin, this example which contains 25% styrene 34.3 Styrene 3.7 Methyl methacrylate 12.3 Ethylene glycol and dimethyl methacrylate 11.1

This paint is sprayed upon wood and metal panels and irradiated as in the previous examples. This coating after 4 passes exhibits a Sward Hardness of about 22.

300 cc. xylene.

A fusion cook of the tetrahydrophthalic anhydride and the neopentyl glycol is carried out until an acid number of about 10 is achieved. Water comes over at about 170 C. and a maximum temperature of about 195 C. is recorded. The charge is cooled to room temperature and the maleic anhydride and diallylether of pentaerythritol are added with the hydroquinone. The charge is heated and reflux starts at about C. Heating is continued for 23 hours. A maximum temperature of C. is recorded and the resin has an acid number of about 9.

A 50% silicone-modified resin is prepared by heating 351.7 parts by weight of above resin and 351.7 parts by weight of dimethyltriphenyltrimethoxytrisiloxane. Methanol comes over at about 122 C. Heating is continued for 2.5 hours and a maximum temperature of 162 C. is recorded. The resin is cooled to 100 C. at which point 0.105 part by weight of hydroquinone is added. The resin is further cooled to 80 C. at which time 210.6 parts by weight styrene is added.

A mill base is prepared by grinding for 20 hours in a pebble mill the following ingredients:

Parts by weight Above silicone-modified resin 300 Tio2 600 Styrene 100 Methyl methacrylate 100 A paint is prepared from the above mill base, styrene, methyl methacrylate and ethylene glycol dimethylacrylate which breaks down as follows:

TiOz percent 32 Vehicle do 68 Resin parts by weight" 50 Styrene do 25 Methyl methacrylate do 25 Ethylene glycol dimethylacrylate do l This paint is sprayed upon wood and metal panels and irradiated as in the previous examples using a potential of 260 kv.

EXAMPLE 9 The procedure of `Example 1 is repeated except that the potential of the electron beam is 175,000 electron volts with the exposure controlled to provide a total dose equivalent to that of Example 1.

EXAMPLE l0 The procedure of Example 1 is repeated except that the potential of the electron beam is about 400,000 volts and the exposure is controlled to provide a total dose equi-vaient to that of Example 1.

The abbreviation mrad as employed herein means y1,000,000 rad. The term rad as employed herein means that dose of radiation which results in the absorption of 100 ergs of energy per gram of absorber, eg. coating film. The electron emitting means may be a linear electron accelerator capable of producing a` direct current potential in the range hereinbefore set forth. In such a device electrons are ordinarily emitted from a hot filament and accelerated through a uniform voltage gradient. The electron beam, .which may be about 1/8" in diameter at this point, is then scanned in one direction to make a fan-shaped beam and then passed through a metal window, e.g. a magnesium-thorium alloy of about 0.003" thickness.

The binder is preferably applied to the substrate and cured thereon as a continuous film of substantially even depth, preferably a depth in the range of about 0.1 to about 4.0 mils depending upon the substrate and the intended end use of the coated product. The paint binder solution advantageously contains about 30 to about 70, preferably 40 to 60 percent of the silicone-modified binder resin and about 30 to about 70, preferably 40 to 60, percent of unpolymerized vinyl monomers. In a preferred embodiment the vinyl monomers of the paint binder are a mixture of about 30 to 70, preferably 40 to 60, and more preferably 45 to 55, percent acrylic monomers with the balance non-acrylic vinyl monomers. For example, increased weathering resistance can be obtained `by increased concentration of an acrylic monomer such as methyl methacrylate -While a lowering of the requisite radiation dosage can be obtained by increasing the concentration of a vinyl hydrocarbon monomer such as styrene and the respective quantities of such monomers may be adjusted to 'fit the individual need. The paint binder may be applied to the substrate by conventional spray techniques, by brushing, roll coating, flow coating, or by the method commonly termed the silk screen process with appropriate adjustment in viscosity. The film-forming material should have a viscosity low enough to permit rapid application to the substrate in substantially even depth and high enough so that a 1 mil (.001) lm will hold upon a vertical surface fwithout sagging. The viscosity of the binder is adjusted by varying the molecular weight of the resin or resins and/ or by varying the relative concentrations of the resin component and/or by varying the relative concentrations of dissimilar monomers within the monomer component. The binder is preferably applied to the substrate essentially free of nonpolymerizable organic solvents and/ or diluents.

The term olefinic unsaturation as used herein refers to the alpha-beta unsaturated acid or anhydride thereof.

rIt will be understood Eby those skilled in the art that modifications can be made :Within the foregoing examples within the scope of the invention as hereinbefore described and hereinafter claimed.

What is claimed is:

1. A method of coating a substrate which comprises applying to said substrate a lm of paint binder comprising a film-forming solution of a silicone-modified organic resin in vinyl monomers copolymerizable with said resin by ionizing radiation, said resin having a molecular weight in excess of about 1,000 and containing about 0.5 to about 3 olefinic unsaturation units per 1,000 units molecular weight and being further characterized in that at least 10 wt. percent thereof is derived from an acyclic siloxane, and copolymerizing said resin and said vinyl monomers upon said substrate with ionizing radiation.

2. A method of coating a substrate which comprises applying to said substrate a film of paint binder comprising a film-forming solution of a silicone-modified polyester resin in vinyl monomers copolymerizable with said resin by ionizing radiation, said resin having a molecular `Weight in excess of about 1,000 and containing about 0.5 to about 3 olefinic unsaturation units per 1,000 units molecular Weight and being further characterized in that at least 10 wt. percent thereof is derived from an acyclic siloxane containing at least 3 silicon atoms per molecule, and copolymerizing said resin and said vinyl monomers upon said substrate with polymerization effecting electrons.

3. A method of coating a substrate which comprises applying to said substrate a film of paint binder comprising a film-forming solution of a silicone-modified polyester resin in vinyl monomers copolymerizable with said resin by ionizing radiation, said resin having a molecular weight in the range of about 2,000 to about 20,000 and containing about 0.5 to about 3 olefinic unsaturation units per 1,000 units molecular weight and being further characterized in that about 15 to about 50 wt. percent thereof is derived from an acyclic siloxane, and copolymerizing said resin and said vinyl monomers upon said substrate with polymerization effecting electrons.

4. A method of coating a substrate which comprises applying to said substrate a yfilm of paint binder comprising a film-forming solution of a silicone-modified organic resin in vinyl monomers copolymerizable with said resin by ionizing radiation, said resin having a molecular -weight in the range of about 1,000 to about 50,000 and containing about 0.5 to about 3 olefinic unsaturation units per 1,000 units molecular weight and being further characterized in that at least 10 Wt. percent thereof is derived from an acyclic siloxane, and copolymerizing said resin and said vinyl monomers upon said substrate with polymerization effecting electrons at a potential in the range of about 150,000 to about 450,000 electron volts.

5. A method of coating a substrate which comprises applying to said substrate a film of paint binder comprising a film-forming solution of a silicone-modified polyester resin in vinyl monomers copolymerizable with said resin by ionizing radiation, said resin having a molecular Weight in excess of about 1,000 and containing about l to about 2 olefinic unsaturation units per 1,000 units molecular weight and being further characterized in that about 15 to about 50 wt. percent thereof is derived from an Si3 to Siu acyclic siloxane, and copolymerizing said resin and said vinyl monomers upon said substrate with polymerization effecting electrons at a potential in the range of about 150,000 to about 450,000 electron volts.

6. A method of coating a substrate which comprises applying to said substrate a film of paint binder having an average depth in the range of about 0.1 to about 4 mils and comprising a film-forming solution of a siliconemodified polyester resin in vinyl monomers copolymerizable with said resin by ionizing radiation, said resin having a molecular weight in excess of about 1,000 and containing about 1.25 to about 1.75 olenic unsaturation units per 1,000 units molecular lweight and being further characterized in that about 20 to about 40 wt. percent thereof is derived from an Si3 to Sim acyclic siloxane, and copolymerizing said resin and said vinyl monomers upon said substrate with polymerization effecting electrons at a potential in the range of about 150,000 to about 450,- 000 electron volts.

7. A method of coating a substrate which comprises applying to said substrate a film of paint binder having an average depth in the range of about 0.1 to about 4 mils and comprising a film-forming solution of a siliconemodied polyester resin in vinyl monomers copolymerizable with said resin by ionizing radiation, said resin having a molecular weight in excess of about 1,000 and containing about 0.5 to about 3 olenic unsaturation units per 1,000 units molecular weight and being further characterized in that about l5 to about 50 wt. percent thereof is derived from an acyclic siloxane, said vinyl monomers comprising a monomer mixture of acrylic monomers and vinyl hydrocarbon monomers, and copolymerizing said resin and said vinyl monomers upon said substrate with polymerization effecting electrons at a potential in the range of about 150,000 to about 450,000 electron volts.

8. A method of coating a substrate which comprises applying to said substrate a film of paint binder having an average depth in the range of about 0.1 to about 4 mils and comprising a film-forming solution of a siliconemodified polyester resin in vinyl monomers copolymerizable with said resin by ionizing radiation, said resin having a molecular weight in the range of about 2,000 to about 20,000 and containing about 1 to about 2 olelinic unsaturation units per 1,000 units molecular weight and being further characterized in that about to about 40 wt. percent thereof is derived from an Si3 to Silz acyclic siloxane, said vinyl monomers comprising a monomer mixture of about 40 to about 60 wt. percent acrylic monomers and about 40 to about 60 wt. percent vinyl hydrocarbon monomers, and copolymerizing said resin and said vinyl monomers upon said substrate with polymerization effecting electrons at a potential in the range of about 150,000 to about 450,000 electron volts.

9. A method of coating a substrate which comprises applying to said substrate a lm of paint binder having an average depth in the range of about 0.1 to about 4 mils and comprising a film-forming solution of a siliconemodified polyester resin in vinyl monomers copolymerizable with said resin by ionizing radiation, said resin having a molecular weight in the range of about 2,000 to about 20,000 and containing about 1 to about 2 olefnic unsaturation units per 1,000 units molecular weight and being further characterized in that about 20 to about 40 wt. percent thereof is derived from an Si?, to Siu acyclic siloxane, said vinyl monomers comprising a monomer mixture containing a major amount of acrylic monomers and a minor amount of vinyl hydrocarbon monomers, and copolymerizing said resin and said vinyl monomers upon said substrate with polymerization effecting electrons at a potential in the range of about 150,000 to about 450,000 electron volts.

10. A method of coating a substrate which comprises applying to said substrate a film-forming solution containing, on a pigment and mineral filler-free basis, about to about 70 wt. percent of a silicone-modied organic resin and about 30 to about 70 wt. percent vinyl monomers copolymerizable with said resin by ionizing radiation, said resin having an average molecular weight in excess of about 1,000 and containing about 0.5 to about 3 olelinic unsaturation units per 1,000 units molecular Weight and being further characterized in that at least l0 wt. percent thereof is derived from an acyclic siloxane containing at least 3 silicon atoms per molecule, and copolymerizing said resin and said vinyl monomers upon said substrate `with polymerization effecting electrons.

11. A method of coating a substrate which comprises applying to said substrate a film-forming solution containing, on a pigment and mineral filler-free basis, about 50 to about wt. percent of a silicone-modified polyester resin and about 30 to about 50 wt. percent vinyl monomers copolymerizable with said resin by ionizing radiation, said resin having an average molecular weight in the range of about 2,000 to about 20,000 and containing about 1 to about 2 olefinic unsaturation units per 1,000 units molecular weight and being further characterized in that about 15 to about 50 wt. percent thereof is derived from an Sig to Silz acyclic siloxane, and copolymerizing said resin and said vinyl monomers upon said substrate with polymerization effecting electrons at a potential in the range of about 150,000 to about 450,000 electron volts.

12. A method of coating a substrate which comprises applying to said substrate a film-forming solution containing, on a pigment and mineral filler-free basis, about 30 to about 50 wt. percent of a silicone-modified polyester resin and about 50i to about 70 wt. percent vinyl monomers copolymerizable with said resin by ionizing radiation, said resin having an average molecular weight in the range of about 2,000 to about 20,000 and containing about 1 to about 2 olefnic unsaturation units per 1,000 units molecular weight and being further characterized in that about 15 to about 50 wt. percent thereof is derived fro-m an Si3 to Sim acyclic siloxane, and copolymerizing said resin and said vinyl monomers upon said substrate with polymerization effecting electrons at a potential in the range of about 150,000 to about 450,000 electron volts.

13. A method of coating a substrate which comprises applying to said substrate a film of paint binder cornprising a film-forming solution of a silicone-modified organic resin in vinyl monomers copolymerizable with said resin by ionizing radiation, said resin having a molecular weight in excess of about 1,000, containing about 0.5 to about 3 olenic unsaturation units pe-l 1,000 units molecular weight and being a copolymer of an acyclic alpha-beta unsaturated dicarboxylic acid or the anhydride thereof, a cyclic aliphatic dicarboxylic acid or the anhydride thereof, a polyhydric alcohol consisting of carbon, hydrogen and oxygen, and an Si3 to S112 acyclic siloxane having a dissociable group selected from the group consisting of hydroxyl radicals and hydrocarbonoxy radicals bonded to at least two of the silicon atoms therein, and copolymerizing said resin and said vinyl monomers upon said substrate with polymerization effecting electrons.

14. A method of coating a substrate which comprises applying to said substrate a film of paint binder having an average depth in the range of about 0.1 to about 4 mils and comprising a film-forming solution of a silicone- Amodified organic resin in vinyl monomers copolymerizable with said resin by ionizing radiation, said resin having a molecular Weight in excess of about 1,000, containing about 1 to about 2 olefinic unsaturation units per 1,000 units molecular Weight and being a copolymer of a polyester resin and an Si?J to Sim acyclic siloxane having a dissociable group selected from the group consisting of hydroxyl radicals and hydrocarbonoxy radicals bonded to at least two of the silicon atoms therein, said polyester being a copolymer of maleic anhydride, tetrahydrophthalic anhydride and a polyhydric alcohol, and copolymerizing said resin and said vinyl monomers upon said substrate with polymerization effecting electrons at a potential in the range of about 150,000 to about 450,000 electron volts.

15. A method of coating a substrate which comprises applying to said substrate a lm of paint binder having an average depth in the range of about 0.1 to about 4 mils and comprising a film-forming solution of a siliconemodified organic resin in vinyl monomers copolymerizable with said resin by ionizing radiation, said resin having a molecular weight in excess of about 1,000, containing about l to about 2 oleinic unsaturation units per 1,000 units molecular weight and formed by reacting a polyhyd-ric alcohol with an Sig to Sim acyclic siloxane having a dissociable group selected from the group consisting of hydroxyl radicals and hydrocarbonoxy radicals bonded to at least two of the silicon atoms and reacting the resulting product with maleic anhydride and tetrahydrophthalic anhydride, and copolymerizing said resin and said vinyl monomers upon said substrate with polymerization effecting electrons at a potential in the range of about 150,000 to about 450,000 electron volts.

16. `In a paint comprising a film-forming solution of vinyl monomers and a paint binder resin, the improvement wherein said paint binder resin is a polyester resin having a molecular weight in excess of about 1,00-0, alpha-beta olefinic unsaturation, and at least two carbon atoms of the principal carbon-to-carbon chain thereof separated by and connected to a divalent acyclic siloxane radical, said resin being further characterized in that about 20 to about 50 wt. percent thereof is derived from an acyclic siloxane containing at least 3 silicon atoms per molecule and said alpha-beta oleiinic unsaturation is limited to a concentration in the range of about 0.5 -to about 3 units per 1,000 units molecular weight.

17. In a paint comprising a film-forming solution of vinyl monomers and a paint binder resin, the improvement wherein said paint binder resin is a polyester resin having a molecular weight in the range of about 2,000

to about 20,000, alpha-beta olefinic unsaturation, and at least two carbon atoms of the principal carbon-to-carbon chain thereof separated by and connected to a divalent acyclic siloxane radical, said resin being further characterized in that about 20 to about 50 wt. percent thereof is derived from an acyclic siloxane containing at least 3 silicon atoms per molecule and said alpha-beta oleiinic unsaturation is limited to a concentration in the range of about 0.5 to about 3 units per 1,000 units molecular weight.

18. In a paint comprising a hlm-forming solution of vinyl monomers and a paint binder resin, the improvement wherein said paint binder resin is a polyester resin having a molecular weight in excess of about 1,000, alpha-beta olefinic unsaturation, and at least two carbon atoms of the principal carbon-to-carbon chain thereof separated by and connected to a divalent acyclic siloxane radical, said resin being further characterized in that about 20 to about 50 wt. percent thereof is derived from an acyclic siloxane containing about 3 to about 12 silicon atoms per molecule and said alpha-beta oletinic unsaturation is limited to a concentration in the range of about 0.5 to about 3 units per 1,000 units molecular weight.

19. In a paint comprising a film-forming solution of vinyl monomers and a paint binder resin, the improvement wherein said paint binder resin is a polyester resin having a molecular weight in the range of about 2,000 to about 20,000, alpha-beta oleinic unsaturation, and at least two carbon atoms of the principal carbon-to-carbon chain thereof separated by and connected to a divalent acyclic siloxane radical, said resin being further characterized in that about 20 to about 40 wt. percent thereof is derived from an acyclic siloxane containing about 3 to about 12 silicon atoms per molecule and said alpha-beta olenic unsaturation is limited to a concentration in the range of about 0.5 to about 3 units per 1,0001 units m0- lecular weight.

20. In a paint comprising a film-forming solution of about 30 to about 70 wt. percent vinyl 4monomers and about 30 to about 70 wt. percent paint binder resin on a pigment and mineral 'liller free basis, the improvement wherein said paint binder resin is a polyester resin havingl a molecular weight in excess of about 1,000, alpha-beta olenic unsaturation, and at least two carbon atoms of the principal carbon-to-carbon chain thereof separated by and connected to a divalent acyclic siloxane radical, said resin being further characterized in that about 20 to about 50 wt, percent thereof is derived from an acyclic siloxane containing at least 3 silicon atoms per lmolecule and said alpha-beta olenic unsaturation is limited to a concentration in the range of about 0.5 to about 3 units per 1,000 units molecular weight.

21. In a paint comprising a hlm-forming solution of vinyl monomers and a paint binder resin, the improvement wherein the paint binder resin is a copolymer of an acyclic alpha-beta unsaturated dicarboxylic acid or the anhydride thereof, a cyclic olefinic dicarboxylic acid or the anhyd-ride thereof, a polyhydric alcohol consisting of carbon, hydrogen and oxygen, and an acyclic siloxane containing about 3 to about 12 silicon atoms per molecule and `having a dissociable group selected from the group consisting of hydroxyl radicals and hydrocarbonoxy radicals bonded to at least two of the silicon atoms therein, said resin being further characterized in that 20 to 50 wt. percent thereof is derived from said acyclic siloxane and in that it has alpha-beta oleiinic unsaturation limited to a concentration in the range of about 0.5 t0 about 3 units per 1,000 units molecular weight.

22. In a paint comprising a film-forming solution of vinyl monomers and a paint binder resin, the improvement wherein said paint binder resin is a copolymer of maleic anhydride, tetrahydrophthalic anhydride, a polyhydric alcohol consisting of carbon, hydrogen and oxygen, and an acyclic siloxane containing about 3 to about 12 silicon atoms per molecule and having a dissociable group selected from the group consisting of hydroxyl radicals and hydrocarbonoxy radicals bonded to at least two of the silicon atoms therein, said resin being further characterized in that 20 to 50 wt. percent thereof is derived from said acyclic siloxane and in that it has alpha-beta olefinic unsaturation limited to a concentration in the range of about 0.5 to about 3 units per 1,000 units molecular weight.

References Cited UNITED STATES PATENTS 2,842,517 7/1958 Shorr 260-827 2,849,527 8/1958 Rogers et al 260-827 2,900,277 8/1959 Schmitz et al. 204159.13 3,065,158 11/1962 Zack 21M-159.13 3,246,054 4/1966 Guenther et al. 1l7-93.31

MURRAY TILLMAN, Prz'nmry Examiner.

JOHN T. GOOLKASIAN, Assistant Examiner.

U.S. Cl. XR. 

